Railway brake structure

ABSTRACT

A RAILWAY BRAKE STRUCTURE INCLUDING BRAKEHEAD AND A LINER, PREFERABLY RENEWABLE, BETWEEN THE HEAD AND THE FRICTION SHOE APPLIED TO THE TRUCK WHEEL. THE LINER MAY BE CONTOURED FOR APPLICATION TO A BRAKEHEAD HAVING A SWING HANGER SUPPORT FROM THE TRUCK FRAME OR IT MAY BE CONTOURED FOR A BRAKEHEAD OR BEAM HAVING A SLIDING SUPPORT ON THE TRUCK FRAME.   PREFERABLY THE LINER WILL BE OF HARDER METAL THAN THE HEAD OR THE SHOE TO BETTER RESIST WEAR AND MORE ACCURATELY POSITION THE SHOE.

United States Patent 1,471,273 10/1923 Lott inventor lrvin J. Spaeth Chicago, 111. Appl. No. 792,245 Filed Jan. 21, 1969 Patented June 28, 1911 Assignee Evans Products Company Plymouth, Mich.

RAILWAY BRAKE STRUCTURE 10 Claims, 9 Drawing Figs.

US. Cl 188/243, 188/236, 188/247 int. Cl B601 7/12 Field 01 Search 188/236, 242, 243, 247, 258, 255

References Cited UNITED STATES PATENTS 1,475,286 11/1923 Crone 188/236 2,266,984 12/1941 Moore 188/242 2,900,711 8/1959 Wilson 188/242X FOREIGN PATENTS 461,075 10/1913 France 188/236 Primary Examiner-George E. A. Halvosa Atrorney- Bedell and Burgess ABSTRACT: A railway brake structure including brakehead and a liner, preferably renewable, between the head and the friction shoe applied to the truck wheel. The liner may be contoured for application to a brakehead having a swing hanger support from the truck frame or it may be contoured for a brakehead or beam having a sliding support on the truck frame. Preferably the liner will be of harder metal than the head or the shoe to better resist wear and more accurately position the shoe.

PATENTED JUN28 1971 FIG.7

INVENTOR IRVI N J. SPAETH BY l AT TOR N EYS RAILWAY BRAKE STRUCTURE BACKGROUND OF THE INVENTION The invention relates primarily to railway truck brakes in which an elongated brake beam extends transversely of the truck 'and carries a brake head on each end. Each head mounts a friction shoe, and a'rclatively thin and narrow spring metal key is driven through recesses in the head and shoe to hold the head and shoe assembled and is readily removed for their disassembly when the shoe is broken or worn and is to be replaced.

SUMMARY OF THE INVENTION Repeated application and release of the brakes to and from the wheels, the vibrations to which the head and shoe are subjected during operation of the truck, and other factors cause the opposing faces of the head and shoe to pound and scrape and wear each other, and sometimes to break, thus shortening the useful life of the parts and reducing their efficiency. Various suggestions have been made to meet the conditions mentioned, such as the insertion of wedges or rubber cushions between the head and shoe or the use of small units or wearresisting metal at critical points, but the construction described below meets the problems encountered more effectively be reason of its ready application, greater effectiveness and more complete support of the shoe on the head.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an end view of a railway brake beam, head and shoe assembly and showing the liner between the head and shoe. 1

FIG. 2 is a front view of the liner showing it applied to the head, which is shown in broken lines, and indicating apertures for the passage ofa retaining key, also shown in broken lines, which holds the head, liner and shoe assembled.

FIGS. 3 and 4 are vertical sections on lines 33 and 4-4 of FIG. 2.

FIG. 5 is a horizontal section through one end of the brake beam on line 5-5 of FIG. 1 without the shoe.

FIG. 6 is a detail vertical section on line 6-6 of FIG. 4 omitting the shoe lug.

FIG. 7 corresponds to FIG. 2 but shows a liner with a modified contour for application to a composition shoe.

FIG. 8 shows a liner applied to a hanger-supported brake beam and the head and liner each has a central notch receiving the lower crossbar of the hanger and the shoe center lug.

FIG. 9 shows the liner applied to a hanger-type beam with the hanger crossbar in the top notch.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The brake beam shown in FIGS. 1-6 is of the truss type and includes a compression member I of channel cross section, a bar or strap tension member 2 with a thickened end shouldered at 3 to engage the end of the compression member. The brake head 4 is preferably of cast steel or pearlitic malleable iron and includes a pocket P opening laterally in one direction to receive the ends of the compression and tension members, and an extension 5 in the opposite direction to slidably engage and support the beam on a truck frame bracket (not shown) in the usual manner for movement to and from the truck wheel indicated at W. A rivet 6 disposed diagonally of the length of the beam secures the head to the end portions of the beam compression and tension members.

Head 4 has an elongated arcuate face with transversely spaced toes 7 at top and bottom and has intermediate lugs 9 with vertical apertures. The head is recesseddeeply at 10 between lugs 9. A brakeshoe II is carried by toes 7 and lugs 9 and has a rearwardly projecting center lug 12 received in the recess-between lugs 9. Brakeshoe Il may be assembled with head 4 by a narrow retaining key 13 of spring metal which is driven through the apertures in lugs 9 and through vertical opening I4 in the shoe lug. All of the foregoing description structure is conventional.

In the present structure as shown in FIGS. 1-7 a liner 15, preferably of spring steel and extending substantially the full length and width of the head face, is applied directly to the head before the shoe is mounted on the head. Intermediate its ends, liner 15 has a U-shaped offset at 16 to enter head recess 10 and extends below, behind and above shoe lug 12. In its initial form, the upper and lower leg portions of the liner offset are spaced-apart and may be distorted toward each other as the liner is applied to the head.Upwardly and downwardly projecting protuberances IS on the liner (FIG. 6) are snugly received with a snap-fitting relationship in cavities 20 in the opposing horizontal walls 22 of the head recess between lugs 9 and frictionally hold the liner in place on the head. The upper and lower ends of the liner are bifurcated deeply at 23 (FIG. 2) and flanged rearwardly at 24 (FIG. I) to project beyond the rear faces of head toes 7 where they may be struck with a hammer to dislodge elements 18 and 20 when the liner is to be removed from the head. The liner has a central aperture 26 which freely receives retaining key 13 (FIGS. 3, 5).

The liner serves as a smooth hard metal backing of uniform thickness, for example three-sixteenths inch, substantially throughout the length and width of the shoe, thus contributing to even wear of the shoe face applied to the wheel and resisting wear between toes 7 and lugs 9. This reduces or eliminates the likelihood of breaking the shoe or head because of unequal pressure or the pounding of loosely fitting head and shoe parts against each other.

The liner as described above is adapted for use with shoes of cast iron having lugs 27 received in deep recesses in the ends of the head, the liner being similarly recessed at 23 (FIG. 2).

Shoes of composition material have a higher coefficient of friction than cast iron shoes and require different brake lever proportions. A worn or broken cast iron shoe should not be replaced with a composition shoe, and vice versa. This is readily prevented by shaping the ends of the liner so that it will not permit a cast iron shoe to be applied thereto and such a liner is shown in FIG. 7 in which the recesses 30 between flanges 29 (corresponding to flanges 24 in FIGS. 1-4 previously described) is so shallow that lugs 27 of the cast iron brakeshoe may not enter irrespective of the shoe mounting face ofthe brake head.

Although the head and brake beam described above is of the hangerless type which is slidably supported on the truck frame brackets, the liner feature may be applied to a head having a hanger-receiving recess at the rear of or spaced above the recess for the shoe lug.

FIG. 8 shows a liner 31 applied to a brakehead 32 suspended by a swing hanger 33 and the liner has a contour fitting in a hanger-receiving recess in the head which is enlarged to receive the lower crossbar 35 of the liner. The liner protuberances 36 enter recesses therefor in the head as previously described and hold the liner to the head.

FIG. 9 is similar to FIG. 8 but shows the offset 41 on the liner 42 shaped to fit into a top recess in head 43 and adapted to partially enclose the lower crossbar 44 of hanger 45. Liner protuberances 46 correspond to protuberance 18, 36 and similarly retain the liner in position in the head.

The liner shown in FIGS. l7 must be applied to the head after the head is assembled with the beam because otherwise the support-engaging extension 5 on the outer end of the beam requires access to the forward end of rivet 6 which may only be had from the front of the head and such access would be blocked by the liner.

The liners for the hanger-type heads of FIGS. 8 and 9 may be applied before or after the head is assembled with the I beam.

The structures described may vary in details without departing from the spirit of the invention and the exclusive use of modifications coming within the scope of the appended claims is contemplated.

[claim g i l, The combination of a railway one piece cast metal and having a horizontally offset portion intermediate its ends extending inwardly of said recess with apertures adapted to receive a shoe-retaining key passed through said head, toes and lug, the opposing faces of said head lugs having cavities and the opposing sides of said liner offset portion having similarly spaced protuberances, said sides being yieldable to permit said protuberances to enter said cavities with a snap fit, said snap fit and key comprising the only means of maintaining said head and liner in assembled relationship.

2. The combination of a one-piece railway brakehead, a readily detachable metal liner and a one-piece brakeshoe, said brake head having laterally spaced forwardly extending shoesupporting toes at top and bottom and a shoe lug-receiving recess intermediate said toes, said liner extending substantially throughout the length and width of said head and overlying said toes, a U-shaped offset portion in said liner received within said recess, snap-fitting means on said liner offset portion and on said head readily detachably connecting said liner to said head, said brakeshoe being fitted over said liner and including an integral lug received in said liner offset portion, and means cooperatively engaged with said head, liner and shoe for holding them in assembled relationship, said snap-fitting means and said cooperating means comprising the only means for securing said liner to said head, said shoe being removable from said head independently of said liner.

3. The combination of a railway brake beam head liner and shoe as described in claim 2, wherein said shoe lug-receiving recess has upper and lower walls and said cooperating means comprises a removable retaining key extending through the upper and lower walls of the recess in the head and through the offset portion of the liner and through said lug and securing the shoe to the head and liner.

4. A railway brakehead liner as described in claim 2 in which the protuberances on the liner offset portion are spaced-apart transversely of the width of the liner and the offset portion is apertured vertically between said spaced protuberances to accommodate the passage of a retaining key through the offset portion intermediate the spaced protuberances.

5. A combination as described in claim 2 in which the brakehead and liner have recesses adapted to receive the lower crossbar of a swing hanger, the portion of the liner forming its hanger-receiving recess fitting within the hanger-receiving recess in the head and preventing wear between the head and the lower crossbar of the hanger.

6. A combination as described in claim 5 in which the liner intermediate its ends has a common recess for receiving the lower crossbar of a hanger and for receiving the center lug of a brakeshoe.

7. A combination as described in claim 2 in which the liner offset portion has legs and the legs and the sides of the lugreceiving recess in the head have internested protuberances and cavities respectively fitting one within the other defining said snap-fitting means to frictionally hold the head and liner against relative sliding movement, the legs of the U-shaped offset portion being distortable toward each other to clear the protuberances from the cavities.

8. A railway brake beam head and liner combination as described in claim 7 in which the liner has end portions projecting rearwardly beyond the head toes and forming elements which may be struck with a hammer to force the protuberances out of the cavities to separate the liner from the head.

9. A railway brakehead and liner combination as described in claim 8 in which the upper'and lower ends of the liner are bifurcated and the bifurcations project rearwardly of the face of the liner for application of a tool during removal of the hanger from the head and there is space between the bifurcatrons to accommodate the lnsertion of a brakeshoe lug between them.

10. A railway brakehead and liner combination as described in claim 8 in which the upper and lower ends of the liner are bifurcated and the bifurcations project rearwardly of the face of the liner for application of a tool during removal of the hanger from the head and there is metal between the inner portions of the bifurcations preventing the insertion of a lug on the rear face ofa brakeshoe between them. 

